Portable hand-held blowers are popularly used by gardeners for home maintenance tasks. These type of a blowers are also used by commercial landscapers, especially for spring and fall clean-up services.
Typical hand-held blowers are either powered by gasoline engines or electric motors. An impeller is connected to the motor or engine and rotates in a chamber within the blower housing. The impeller generates an air flow that is directed towards an outlet port on the blower housing. A tube or pipe is generally connected to the outlet port of the blower housing to direct the air flow from the blower housing to the debris.
It is advantageous for a user to adjust the velocity of the air flow leaving the blower tube for specific jobs. For example, hand-held blowers are of ten used to clear leaves from gutters or wash drains. Air flow velocity exiting the standard tube of the blower is typically not strong enough to remove leaves and debris from the drains.
In order to solve this air flow velocity problem, prior art hand-held blowers have required an operator to use a series of attachments to change the air flow of the blower. Most blowers are provided with a wide angle nozzle attachment for disbursed air flow and a restricted nozzle attachment for providing a directed air flow. These attachments are typically mounted at the exit opening of the tube of the blower.
One of the problems associated with the use of multiple nozzle attachments is that each attachment can provide only one type of air flow velocity. To change between a lower velocity air flow and a higher velocity air flow, an operator has to change the attachment heads from the wide angle nozzle attachment to the directed air flow nozzle attachment. Using the different nozzle attachments to change air flow velocity is inconvenient for the user, as the user must carry both nozzle, attachments in case more than one attachment may be necessary to complete the blowing operation.
Other types of devices have previously adopted the concept of restricting fluid flow through an exit opening. An example of one such prior art device is U.S. Pat. No. 4,097,722 issued to Soler et al. The Soler patent discloses an electric hand-held hair dryer including an air deflecting damper in the exhaust barrel of the hair dryer. The air deflecting damper is operatively positioned between a first position and a second position by a spring biased trigger that extends towards the handle of the hair dryer. The air deflecting damper can only be locked into one of two positions, allowing either a dispersed air flow or a concentrated air flow. The air deflecting damper does not direct the entire air stream towards the exit opening of the dryer. Instead, air escape can flow around the air deflecting damper in the hair dryer nozzle, making the hair dryer less efficient in directing the restricted air flow.
U.S. Pat. No. 3,003,706 issued to Thorne discloses a nozzle attachment for a garden hose. The Thorne patent provides an internally mounted flap that can be adjusted to a variety of positions to allow a user issue a wide, fan-shaped spray or a concentrated spray of water for long distances as desired. The flap is adjusted to a variety of positions by an externally mounted control lever. The lever is operable by the finger or thumb of the user to provide a variety of water velocities. This arrangement requires the user to manually intervene to operate the control lever during the watering operation if a restricted fluid flow is desired.
These and other problems and disadvantages encountered by the prior art are overcome by the present invention as summarized below.